Automatic control unit for jet deep well pump



Nov. 4, 1958 "r. s. HARRIS 2,358,341

AUTOMATIC con'moz. UNIT FOR JET DEEP WELL PUMP Filed Nov. 3, 1954 2 Sheets-Sheet 1 INVENT OR Maj $444.2

Nov. 4, 1958 T. s. HARRlS 2,858,841

AUTOMATIC CONTROL UNIT FOR JET DEEP WELL PUMP Filed Nov. 3, 1954 2 Sheets-Sheet 2 INVENTOR MAM United States Patent 2,858,841 AUTOMATIC CONTROL UNIT FOR JET DEEP WELL PUMP Thaddeus S. Harris, Waverly, Ill. Application November 3, 1954, Serial No. 466,603 6 Claims. (Cl. 13787) The purpose of this invention is to provide new and improved means for controlling the operation of a jet type deep well pump of the centrifugal type, particular reference being had to the operation of domestic water systems, and at low water levels where a jet pump tends to become unreliable in operation, if the well inflow is less than the pump capacity.

This invention is a further development of features which have been disclosed in my Patent No. 2,630,069 issued March 3, 1953, and also in my Patent No. 2,409,- 561 issued October 15, 1946. But the present disclosure is much more than the mere sum of these former disclosures.

Figure 1 of the drawings shows a median section of the most extended form of this control unit.

Figure 2 shows a surface view of a complete pumping installation, to illustrate how this control unit is to be connected to the pump and storage tank.

Referring to Figure l, the main control valve casing, 1 has the intake port, 2 and the discharge port, 3. The diaphragm, 4 extends across the open end of casing, 1 at the end opposite to port, 2. Valve member, 5 is fixed to diaphragm, 4 with the valve, 5 controlling port, 2 and with the spring 6 disposed to hold valve, 5 closed.

An auxiliary control chamber comprises the casing, 11, which is fixed to the main control casing, 1, with the opening, 12 being aligned with the opening, 12' in the wall of the main casing, 1 to form a passage from casing 1 to casing 11. A flexible membrane, 13 is held between the two casings and across the passage otherwise formed by the adjacent openings, 12, and 12'.

The control lever, 14 extends through, and is fixed to the membrane, 13. One end of lever, 14 engages a slot 15 in valve member, 5, while the opposite end of lever 14 extends into the auxiliary casing 11. The diaphragm 18 is extended across the open end of the auxiliary casing 11 and a spring 17 is disposed to hold the diaphragm 18 against the casing cap, 19. An arm 21) is fixed to diaphragm l8 and is disposed to engage lever 14 when spring 17 is compressed, by upward movement of diaphragm 18.

The diaphragm 18 has the center post 18 which extends through an opening in casing cap 19, and has fixed to it the cam block 21. Supplementary springs 22, 23 are fixed to the casing cap 19, with adjusting screws 22' and 23, and with their free ends suitably formed and disposed to engage cam block 21.

The auxiliary control casing 11 has the port 24, and also the small controlled port 25. Port 25 has the control valve 26 which is normally held closed by spring 27. Valve rod 28 is extended to be engaged by the control lever 14 so that valve 26 is forced open when valve 5 is almost closed.

A small diaphragm chamber casing 29 is fixed to casing 1 by the pipe 30. The diaphragm 31 is extended across the open face of casing 29. The centerpost 32 of diaphragm 31 is extended to barely engage diaphragm 4 when valve member 5 is forced upward to open port 2. A spring 33 is disposed to normally hold diaphragm 31 against stop 34.

Referring to Figure 2, the pump 37 is direct connected to motor 36 which is controlled by pressure switch 39. The control unit 1, 11, has the intake port 2 connected to the discharge outlet 40 of the pump. The disice charge port 3 of the control unit is connected to tank 41 by pipe 42. The intake passage 43 of pump 37 is connected by pipe 44 to the top of the venturi 45 of the jet unit 46. The bottom of the venturi is connected by pipe 47 to the water of the well, with the foot valve 48 connected into pipe 47. The discharge outlet 41) of the pump is also connected by pipe 49 to the jet of the jet unit 46. The auxiliary casing port 24 of Figure l is connected by pipes 50 and 44 to the pump intake passage 43.

In describing the operation of this control unit, it must be understood how it is a dependable and basic principle of jet deep well operation that, with the drive remaining approximately constant, as herein provided, the degree of pressure, or partial vacuum, which builds up in the intake to the operating pump, varies widely to increase as the water level in the well goes lower, to thus increase the required vertical lift. it is this variation and increase in intake vacuum which this automatic control unit utilizes to give automatic control over the operation of the pump, especially at very low water levels where, if the well inflow is less than the pump capacity, the water may, on a long period of operation, go so low, that air enters the piping to permanently put the pump completely out of operation, so far as lifting any water is concerned. This is especially liable to occur in case of a small bored well which has almost no storage capacity.

Or, the intake vacuum may eventually go so high that the intake water column breaks so sufficient water ceases to go to the pump, with the result that it goes out of operation because of collapse of drive pressure to energize the jet. This occurs whenever the water level goes lower than the particular jet being used, is suited to operate at. Both, or either of these troubles is avoided by the use of this automatic control unit.

By referring to Figure 2 it can be seen that the pipes 44, 50 will communicate the intake partial vacuum to the auxiliary casing chamber of the control unit. When this degree of vacuum reaches about 10 pounds or l2 pounds, according to the setting of the auxiliary springs, then the pull on the diaphragm 18 begins to overcome the holding power of the auxiliary springs which support diaphragm 18, so that the diaphragm moves, with arm 20 contacting the end of lever 14, with the result that a secondary pressure is communicated to the main control valve 5, tending to more nearly close it.

As valve 5 becomes more nearly closed less water flows to the tank while more water must go to the jet unit in the well. This somewhat increases the lifting power of the jet. But the primary purpose of this movement of valve 5 is to decrease the flow to the tank to thereby decrease the take from the well these two items always being the same. And this also contributes to maintaining drive pressure which tends to decrease when the intake vacuum becomes very high.

If the need for automatic correction is not very great these influences alone may be suflicient to control the pump to prevent loss of priming. But if the capacity of the pump, even at low water levels is still much greater than is the well inflow then the water level continues to go lower and the intake vacuum eventually becomes so high that the further movement of lever 14, under pressure from arm 20 causes the feed back valve 26 to open to allow a feed back flow to the intake pipe from the discharge flow which normally goes to the tank.

Thus this opening of valve 26 not only relieves the excessive intake vacuum but it also helps to reduce the net flow to the tank. So the operation of valves 5 and 26 supplement each other when the need becomes greater, with either alone sometimes being suihcient, and with the total, final, single result of preventing the pump from losing prime, either by overdrawing the well, to admit air to the piping, or because the required lift ceases to be sufliciently taken care of by the jet, to cause collapse of drive pressure.

Of course, as a prerequisite to the above described operation of this control unit, the jet unit must be properly proportioned to the well in which it is to operate. Namely, in case of a one hundred foot well the jet must or may be so proportioned that the maximum lift will be about one hundred feet. In other words when the water level in the well has fallen to about the end of the piping the intake vacuum will be running about twelve pounds of vacuum. And it is a special advantage of using this control unit, that to thus proportion the jet is not ordinarily practical, lest trouble occur from overdrawing the well. so ordinarily no attempt is made to use the lower part of the well where the well inflow is much greater.

But when this automatic control is used the best part of the well becomes usable. For, then, after the installation is completed, if it should be found that the well is overdrawn on a long period of operation the setting of the auxiliary springs may be loosened to put the pump on to automatic and eventually balanced operation at a little higher water level, thus allowing the well to be used down very close to the bottom, but with no danger of incurable trouble on a long period of operation. Thus, besides the assurance of trouble free operation, this automatic control also materially improves the usable inflow capacity of the well.

It is to be understood that this control unit is entirely operable when using only the coil spring to control movements of the auxiliary diaphragm. The advantage of using the flat springs also, is that the automatic change over from normal to balanced operation then takes place with something approaching snap action, while this change over is accomplished more gradually when the coil spring alone is used.

Also, the balancing diaphragm chamber, 29 is not required except when the maximum pressure is set to go well above that minimum pressure which is produced by the main valve 5. When the cut out switch is set to stop the pump at say sixty pounds pressure instead of forty pounds, then the pressure under valve runs so high that it interferes with the automatic influence coming from the auxiliary control. In such an instance the use of the balancing diaphragm chamber 29 serves to communicate a pressure to the top end of valve member 5, to balance against the increase of drive pressure, when it goes above forty pounds.

It is worthy of careful note how the operation of valve 5 is balanced against variations in the tank pressure, which pressure is at all times communicated back to the interior of the main casing 1. As indicated by the dotted lines ab and c-d the working diameter of diaphragm 4 is the same as that of valve 5, in order that the pressure from within chamber 1 may not communicate any tendency to move valve 5 either up or down. By working diameter" as used in this case is meant the diameter of a circular area on diaphragm 4 on which the pressure is always equal and opposite to that on valve 5 as shown by the dotted lines. The annular portion of diaphragm 4 surrounding this circular area and Within the circular opening in the casing cap thus becomes an ineffective pressure area since any pressure on this area must be supported from or by the fixed cap 9, and therefore would not at all affect the movements of valve 5. More exactly it means the distance from the middle of the flexible portion on one side to the middle on the opposite side. Also valve 5 should not open on less than the maximum tank pressure.

I claim as new:

1. In an automatically controlled pumping plant, the combination of a pump, a motor adapted to operate said pump, a storage tank, a jet unit having a venturi disposed at a level below said pump, an intake passage from said jet unit into said pump, a discharge passage from said pump, a pipe extended from said intake passage to the top of the venturi of said jet unit, a second pipe extended from the bottom of said venturi to the water surrounding the jet unit, a check valve in said second pipe; an automatic control unit, said unit comprising a main cylindrical casing, a flexible diaphragm extended across an opening in the top of said main casing, an intake port into the bottom of said main casing connected to said pump discharge passage, a main control valve member disposed to control said port, said valve member being fixed to the center of said diaphragm, a spring disposed to close said valve, a closed passage from said intake port to said pump discharge passage, also a pipe extended from said pump discharge passage to the jet of said jet unit, a discharge port from one side of said main casing, a passage extended from said discharge port to said storage tank, an extended opening in the opposite side of said main casing; an auxiliary cylindrical casing, an extended opening in one side of said auxiliary casing, said auxiliary casing being fixed to said main casing with said openings aligned with each other, but with a flexible membrane held extended across said openings a valve lever passing through and supported by said flexible membrane, one end of said lever engaging said main valve member while the opposite and free end extends into said auxiliary casing, a port from the opposite side of said auxiliary casing, a passage extending from said port to said pump intake pasage, a diaphragm supported across one end of said auxiliary casing by a circular cap, an opening through the center of said cap, a center-post fixed to said diaphragm and extended through said cap opening, an adjustable block on said center-post, a pair of flat opposing springs attached to said cap and with rounded ends adapted to engage said block, also a coil spring disposed to move said diaphragm toward said cap, a small port from the opposite end of said auxiliary casing, a passage from said port to the interior of said main casing, a feed back valve disposed to control said port, a spring disposed to normally close said valve, an arm extended from said auxiliary diaphragm, said arm being disposed to engage said free end of said valve lever to thereby put said auxiliary diaphragm into operable connection with said main control valve and also into connection with said feed back valve.

2. In a jet deep well pump installation having an intake pipe an automatic control unit to, automatically take over control of the vacuum in the top of the intake pipe at any chosen level of water in the well, while simultaneously also decreasing the net flow to a storage tank, said unit comprising a main cylindrical casing, a flexible diaphragm supported across an opening into the top of said casing, an intake port into the bottom of said casing, a main control valve member disposed to control said port, said valve member being fixed to said diaphragm, a spring disposed to normally close said valve, a discharge port from one side of said main casing, said port communicating with said tank an extended opening in the side of said main casing; an auxiliary cylindrical casing, an extended opening in one side of said auxiliary casing, said auxiliary casing being fixed to said main casing with said openings aligned with each other, but with a flexible membrane held extended across said openings, a valve lever extended through and supported by r said flexible membrane, one end of said lever engaging said main valve member, while the opposite and free end extends into said auxiliary casing, a port from the side of said auxiliary casing, said port communicating with said intake pipe a diaphragm across one end of said auxiliary casing, a circular cap in supporting relationship with said diaphragm, an opening through the center of said cap, a center-post fixed to said diaphragm and extended through said cap opening, an adjustable block on said center-post, a pair of flat, opposing springs attached to said cap with rounded ends adapted to engage said block, also a coil spring disposed to move said diaphragm towards said cap; a small feed back port from the oppo site end of said auxiliary casing, a passage from said small port to the interior of said main casing, a feed back valve assembly disposed to control said port, a spring disposed to hold said valve normally closed an arm extended from said auxiliary diaphragm, said arm being disposed to engage said free end of said valve lever to thereby put said auxiliary diaphragm into operable connection with said main control valve and also into operable connection with said feed back valve assembly.

3. In a jet deep well pump installation having an intake pipe an automatic control unit to automatically take over control of the vacuum in the top of the intake pipe at any chosen level of water in the well, while simultaneously also decreasing the net flow to a storage tank, said unit comprising a main cylindrical casing, a flexible diaphragm supported across an opening in the top of said casing, an intake port into the bottom of said casing. a main control valve member disposed to control said port, said valve member being fixed to said diaphragm, a spring disposed to hold said valve closed, a discharge port from one side of said main casing, said port communicating with said tank an extended opening in the opposite side of said main casing; an auxiliary cylindrical casing, an extended opening in one side of said auxiliary casing, said auxiliary casing being fixed to said main casing with said openings aligned, but with a flexible membrane held extended across said opening, a valve lever extended through and supported by said flexible membrane held extended across said openings, a valve valve member, while the opposite free end extends into said auxiliary casing, a port from the opposite side of said auxiliary casing, said port communicating with said intake pipe an auxiliary diaphragm supported across one end of said auxiliary casing by a circular ring, a spring disposed to move said auxiliary diaphragm towards said ring, a small feed back port into said auxiliary casing, opposite to said auxiliary diaphragm, a passage extended from said small port to the interior of said main casing, a feed back valve disposed to control said port, a spring disposed to normally hold said feed back valve closed, an arm fixed to said auxiliary diaphragm, said arm being extended to engage said free end of said valve lever to thereby put said auxiliary diaphragm into operable rely-w tion with said main valve, and also, through said valve lever, into operable connection with said feed back valve, when said auxiliary diaphragm moves away from said supporting ring.

4. In a jet deep well pump installation an automatic control unit to, automatically reduce the discharge fiow to the storage tank at any chosen level of water in the well, while simultaneously also reducing an excessive vacuum in the intake pipe, said control unit comprising a main cylindrical casing, a diaphragm supported across an opening in the top of said casing, an intake port into the opposite end of said main casing, a main control valve member disposed to control said port, said valve member being fixed to said diaphrgram, a spring disposed to normally close said valve, a discharge port from one side of said main casing, said discharge port communicating with said tank, an extended opening in the side of said main casing; an auxiliary cylindrical casing, an extended opening in one side of said auxiliary casing, said auxiliary casing being fixed to said main casing with said opening; aligned but with a flexible membrane held across said openings, a valve lever extended through, and supported by said flexible membrane, one end of said lever engaging said main valve member, While the opposite and free end extends into said auxiliary casing, a port from the side of said auxiliary casing, said port communicating with said intake pipe, a diaphragm supported across one end of said auxiliary casing by a supporting ring, a spring disposed to move said diaphragm toward said ring, an arm fixed to said diaphragm and extended to engage said free end of said valve lever to thereby put said auxiliary diaphragm into operable relation with said main valve.

5. In a jet deep well pump installation having an intake pipe an automatic control unit to, automatically take over control of the partial vacuum in the intake pipe at any chosen level of water in the well, while simultaneously, also, decreasing the net flow to the storage tank, said control unit comprising the combination of a main cylindrical casing, a diaphragm supported across an opening in one end of said main casing, an intake port into the opposite end of said casing, a valve member disposed to control said port, said valve member being fixed to said diaphragm, said diaphragm being of such dimension that a circle which defines that portion of said diaphragm that is supported from said valve member, is of approxi mately the same diameter as is said valve member a spring disposed to normally hold said valve closed, a discharge port from one side of said casing, said discharge port communicating with said tank a cylindrical auxiliary casing, said auxiliary casing being fixed to said main casing, a flexible diaphragm supported across an opening in one end of said auxiliary casing, by a circular ring, a spring disposed to move said flexible diaphragm towards said supporting ring, an uncontrolled port from said auxiliary casing, said uncontrolled port communicating with said intake pipe, a controlled feed back port into said flexible opposite to said flexible diaphragm, a passage from said controlled port to the interior of said main casing, a valve assembly disposed to control said feed back port a spring disposed to normally hold said valve assembly closed, and an arm fixed to said auxiliary casing diaphragm, said arm being extended to operatively engage said valve assembly when said flexible diaphragm moves away from said supporting ring.

6. In a jet deep well pump installation having a storage tank and an intake pipe an automatic control unit to, automatically take over control of the partial vacuum in the intake pipe, at any chosen level of water in the well, while simultaneously, also, decreasing the net flow to the storage tank, said control unit comprising the combination of a main cylindrical casing, a diaphragm supported across an opening in one end of said main casing, an intake port into the opposite end of said casing, a valve member disposed to control said port, said valve member being fixed to said diaphragm, said diaphragm being of such dimension that a circle which defines that portion of said diaphragm that is supported from said valve member, is of approximately the same diameter as is said valve member, a spring disposed to normally hold said valve closed, a discharge port from one side of said casing, said discharge port communicating with said tank, a cylindrical auxiliary casing, said auxiliary casing being closely associated with said main casing, a flexible diaphragm supported across an opening in one end of said auxiliary casing by a circular ring, a spring disposed to normally hold said flexible diaphragm away from said auxiliary casing, an uncontrolled port from said auxiliary casing, said port communicating with said intake pipe, a controlled feed back port into said auxiliary casing, said controlled port communicating with the interior of said tank, a valve assembly disposed to control said controlled port, a spring disposed to normally hold said valve assembly closed, and an arm fixed to said flexible diaphragm, said arm being extended to operably engage said valve assembly when said flexible diaphragm is moved away from said circular ring, to cause said valve assembly to take an open position.

References Cited in the file of this patent UNITED STATES PATENTS 1,157,957 Pfau Oct. 26, 1915 2,409,561 Harris Oct. 15, 1946 2,573,231 Teague Oct. 30, 1951 2,608,157 Conery Aug. 26, 1952 2,630,069 Harris Mar. 3, 1953 

